Piston packing



June 26, 1923., 1,460,182

. K. A. SFMMON PISTON PACKING Filed April 9, 1919 WITNESSES: INVENTOR ffar/ AS/mmon. %.a BY

ATTORNEY Patented June 26, 1923.

UNITED s-Tss t lL- ON, F EDGEWOOD PARK, PI'LINSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF vPENN- BVANIA.

PATENT orrlcae PISTON PACKING.

Application filed April 9, 1819. Serial No. 288,8.

To all whom it may com-em:

Be it known that I, KARL A. SIMMON, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Piston Packings, of which the following is a secification.

invention relates to control apparatus 1 of the fluid-operated type, and particularly to piston pac ing for use in the air cylinders that are commonly employed in railway-motor-control systems of the electropneumatic type.

The object of my invention is to provide a piston packing comprising a layer of relatively. porous material sandwiched between layers of dissimilar fibrous material for producing a packing that is impervious to fluid pressure. a

More specifically stated, it is the object ofmy invention to provide a piston packing comprising alternate layers ol inferiorgrade leather which is p'enetrable by air at pressure, and closely woven fibrous material, such as paper or treated cloth, wlr-ch is impervious to air pressure, whereby a relatively inexpensive, but thorcugl'ily reliable and durable, piston packing 15 se- 39 cured.

My. invention may best be underst od by reference to the accompanying drawing, wherein the single figure is a view, in longitudinal section, of a piston-and-cylinder de vice which embodies a piston packing constructed in accordance with the present invention. t

Rafe to the drawing, the structure here shown comprises a piston rod 1, the W lower end of which is fitted with a piston 2 for traveling within an operating cylinder.

3,-the piston being biased towards the illustrated lower position by means of a coil ie the resent invention is particularly adapted or use in connection with the illustrated type of air cylinders for operating the well-hown unit switches, it will be understood that the invention is not so re- W stricted in its application, but may be em-' ployed in any case where a relat e y inexpensive piston packing impervious .to air pressure is desired.

The lower end 10 of the iston rod 1 is of reduced diameter, to provide a suitable annular shoulder against which the piston 2 is assembled. The iston comprises a supporting plate or waslier 11, which is placed in direct engagement with the above-mentioned shoulder, a resilient backing or dished plate 12 of a familiar type, three layers 13 of relatively porous material, such as inferior-grade leather, a plurality of layers 14 sandwiched between the layers of leather 13, and composed of some closely Woven or non-porous material, such as paper or treated cloth or flexible metal sheets, and

a cup-shaped supporting and stop member 15, the entire piston being tightly positioned upon the reduced-diameter portion 10 of the piston rod by means of a suitable lockwasher 16 and nut 17, in accordance with a familiar practise.

It will be seen that I have thus provided a piston packing which is impervious to air pressure, and is of durable construction, but which is relatively inexpensive, bv reason of employin'" an-inferior grade of leather which it has not been previously possible to utilize because of its great porosity. ile the invention is especially adapted to use with such low-grade leather, if desired, high-quality leather may be utilized to more completely seal the pores therein, and thus enable a higher degree of air-pressurethan before to be successfully used.

It will be appreciated that my invention Y is not restricted to the specific embodiment grade leather and non-porous fibrous material located on oppositesidesthereof for sealing the leather pores.

' 3. piston packmg comprising alternate layers of inferior-grade leather penetrable 5 by air-pressure and closely-woven fibrous material- IIDPGI'VIOHS to air-pressure.

4. A cup piston packing comprising a layer of relatively porous material sand- KARL A. SIMMON. 

